For example, Patent Literature 1 discloses an illumination apparatus for adjusting an angle of an illumination lamp installed on a ceiling by operating movable switches in a switch box attached to a wall. This illumination apparatus has a horizontal driving unit that drives an illumination lamp in the horizontal direction and a vertical driving unit that drives the illumination lamp in the vertical direction disposed in a vertical row, and the total length thereof becomes long. Accordingly, an angle adjuster is desired to be reduced in size, for example, for applying the angle adjuster to a ceiling-embedded downlight.